Focusing arc lamp



Jam 4, 1927. 1,613,003

- MV 4. WOHL FOCUS ING ARC LAMP Filed April 10, 1922 2 Sheets-Sheet 1L W INVENTOR fizz? ATTORNEY Jan. 4 1927. 1,613,003

- M. J. WOHL FOCUSING ARC LAMP Filed Apr il 10, 1922 2 sums-sheet 2 1,14 ATTORNEY Patented Jan. 4, 1927.

UNITED STATES MAURICE J. WOHL, OF NEW YORK, N. Y.,

PATENT QFFICE.

ASSIGNOR TO M. J. WVOHL & CO. INC, OF

LONG ISLAND CITY, NEW YORK, A CCRPORATION OF NEW YORK.

FOCUSING ARC LAMP.

Application filed April 10, 1922.

This invention relates to are lamps of the focusing type and particularly to hand operated lamps which are especially designed to.- use in the photographic studio and for the production of motion picture films.

It is the object (it the present invention to provide a lamp for photographic illumination, which is extremely light in weight and therefore may easily be carried from place to place in the studio when placed on a suitable support.

It is another object of the invention to provide a lamp which, although its carbons are fed by hand, requires no careful adjustment by the photographer to produce and maintain an arc.

It is a further object of the invention to provide a relatively small lamp which permits the use of high currents and consequently gives a high. candle power.

With these and other objects in view, the invention consists in a novel arrangement of parts and details o'l construction hereinafter fully described and finally pointed out in the claims.

In the drawings forming a part of these s 'iecilications liigure I is a side elevation of the lamp mechanism showing the lamp housing in sec-- tion, on its central vertical plane; some of the parts being broken out to show details otherwise covered.

Figure II. is a sectional elevation on the plane indicated by the line II-II of Figure I.

Figure III is a detail plan view. of the negative carbon holder on the plane indicated bv the line III-III of Figure I.

Figure IV is a plan view of the positive carbon mechanism on the plane indicated by the line IV-IV of Figure I.

liig'ure V is a front elevation oi Figure IV on the plane indicated by the line V--V of that figure and looking in the direction of the arrows.

Figure VI is a side elevation of the negative carbon mechanism partly in section on the plane indicated by the line VIVI of Figure VII.

Figure VII is a front view of the inclined negative carbon support, seen perperulicular to the inclined carbon of Fig. VI.

Figure VIII is a detail of negative carbon supporthridge.

Serial No. 551,233.

Figure IX is a side elevation of the complete lamp in its housing.

Referring to Figure l of the drawing, A. is the lamp housing suitably supported by a segmental bracket B on a stand or pedestal C. The bracket, and with it the lamp, may swivel about a pivot pin C through an angle of 45 to either side ot the vertical line. The front plate A of the lamp housing holds the condenser lens L, and the rear plate A is provided with a horizontalcylindrical extension A closed at its lCt end. l ear the bottom plate A of the housnig, two paralle horizontal rods D forming a track for the lamp mechanism are held by bosses of the plates A and A Each rod carries a sleeve D These two sleeves are joined by a trans verse bridge piece D from which rises vertically the supporting plate for the positive carbon mechanism I 1 and from which extends horizontally the support for the neg ative carbon mechanism F To the bridge piece I) is also fastened, between the rods D a horizontal sliding bar I) which is guided in a l'iushing of rear plate A and is provided with a large knob or handle D, outside of the lamp housing. The plate E joined to a flullltll' but shorter plate E arranged parallel thereto, by the two track rods E and the bottom rod Ff. The plate and the whole positive carbon mechanism are of such size that they can be accommodated in the extension A when shifted rearwardly by means oi knob D. The bridge E (see Figure IV) is slidably mounted on rods E by meai'is of sleeves E Plate E is held insulated on E and carries the carbon holder check ll*l l "tor the positive carbon electrode E in the focal axis of the lens. The tree end of carbon E extends freely through plate E and is guided in the insulated plate E which is fastened to the front side of I1 Plates IQ and E are joined by the flexible coiujliu-- tor E.

The horizontal plate F is bent upwardly in its forward part approximately l5 degrees, and widened transversely in T-sha'pe to form the bracket F see Figures I, VI and VII). This bracket carries two inclined track rods F on which sleeves l slide, be ing joined by bridge E which carries on its rear side, insulated therefrom, a rectangular yoke F in which swings the fork This (ill ti LI fork is a part ot a curved lever F and is pivoted on pin 13. The lever F is provided at its free end with. a weight F The bridge F holds in the vertical plane of the lamp axis a shouldered collar F sliding); freely therein for a distance limited by the shoulders a and l). The lower end of this collar is formed into a fork which straddles the lever F a pin F held transversely in this fork limiting the downward movement of this lever. in insulating bushing; is held in an ax al aperture of collar F. This bushing forms the upper shoulder a and holds in a ta )ped axial bore a screw F which forms the lower end of the negative carbon holder chuck F -J Thisv chuck holds the negative carbon electrode i The are forming-end of carbon F guided in an angular slot in transverse bridge i held between the upper ends of rods r". This bridge is joined electrically by llcxible conductor F to the lower bridge l An endless chain (3:, (Fig. fastened to bridge E at point (5, runs from roller G held in an aperture of plate E then over roller G in plate E and freel through voke F and fork 8 of lever l. over roller G in plate F and returns in upward direction. The chain is fastened to yoke I and from there runs over roller G" held in plate E (below roller G to roller G and plate Between rollers G and G helical tension spring G is slipped over the chain to hold it taut on the various rollers. he ends of the 5 )ring are held in extended position by two of the chain links, oetween wiiich the chain is slack within the coil of the sprinq. The end of a second chain H is fastened by means of an eye H to the upper face of one prong ot' the tork 8 of lever i. This chain runs over roller H mounted on the same a is with roller G in an aperture of plate E From there it runs over roller H mounted on rear plate A and through an aperture in this plate to the outside of the housing, it depends vertically therefrom and terminates in a little weight H" which forms a handle.

Current enters the lamp through a cable, the ends of which connected to terminals J. on plate E, of the positive and K on plate ot' the negative carbon supports. The operation of this lamp as follows: irssnming the points of the carbon electrodes to be far apart, a pull on the weight ll: and chain H will swing lever F on pin l littinp; weip'ht F until the lever strikes the face c of collar F The ran pull will then cause the bushing F to slide upwardly in l until shoulder Z) strikes the lower face "hereof. which also pushes the negative car- )Oll electrode upwardly. The still continued ll on chain H causes the bridge F and *lttfi't" to move upwardly on the rods F .1211; ...9 negative carbon strikes the positive carbon E. It the hand now removed from weight H", the lever F is released from the upward pull of chain H. and weight F will cause it to tall back on pin F and pull collar F the negative carbon holder and carbon F downwardly until shoulder a strikes the upper face of if. Thisv action strikes an are between the electrodes the length or which is equal to the travel of collar F in F. As the lower line ot endless chain irfastened to yoke .F and the upper line to bridge E ot the positive carbon mechanism, these points ot fastening move in opposite direction when this chain moves on its rollers. The action heretofore dese -ibed has moved the yoke F and consemienily also the chain fastened thereto upwardlv. lt mores thei'eo also the plate ll lorwardlv and with it the positive carbon. it should be noticed. however, that the movement ot' the chain ti does not commence until lever 1 and b ing F are tullv lifted and that it ceases as soon as the hand is removed from This feeding action may be repeated as often as the ar: requires an adjustment, it is independent of the length o't either carbon. as the pull on the chain H will move them both until they meet and when released strike the arc. The screw F" permits an adjustment of the negative carbon to bring it the required distance above bridge F to hold the arc in its proper place and to adjust for unequal burning of the carbons caused by varying densit in the mass of the electrode. The whole lamp mechanism can easily be shifted by means of knob D and rod D on rods D to vary its distance from the lens L.

In addition to the current entry through the carbon holders the current is carried by plates 11] and F close to the points at both electrodes which permits a high current dent-it at the arc in both electrodes.

The weight F is so placed that the are striking action is not ali'ected by tilting the lamp through an angle ot' degrees.

The striking distance of the arc is so predetermined that the shortest satisfactory burning are length "for the current. passing is struck. Inasmuch as there is no automatic feeding; mechanism, the arc length increases with the time of burning. The required burning period in most users tor which this type of lamp is designed is normally so short thata second striking ol the arc is unnecessary. However, where longer periods oi operation are needed, an intermittent pull on the striking chain at 2 or 3 minute intervals rill keep the lamp burning at a satisfactory const'anc of light strength.

l claim: 7 i

1. In an arc lamp a pair of are forming electrodes, a support for each electrode, a n'iovable holder on one of said supports Ian carrying an electrode, means on said holder to raise the electrode thereon while said holder is stationary, a stop to limit the raising movement, means to lift said holder when the electrode is in raised position until the electrodes form a contact and means to lower the electrode in its holder to form an arc of predetermined length when said lifting means are released.

2. In an arc lamp a pair of are forming electrodes, a support for each electrode, common means to move said electrode-supports simultaneously until the electrodes form a contact with each other, an electrode lifting lever on one of said supports forming means to move the electrode on said support, and other means to first operate said lifting lever, and then said means for moving the electrodes simultaneously.

3. In an arc lamp, a pair of are forming electrodes, a support for each electrode, an endless chain arranged to move said electrodes toward each other and means adapted for remote manual operation to move said chain and said electrodes towards each other until their tips come together and means on one of said supports to open arc-space of fixed length between said electrodes upon release of said manually operated means.

l. In an arc lamp, a pair of are forming electrodes, a support for each electrode, a movable holder on each support, means on one holder to lift the electrode thereon, a stop to limit the lifting distance, and means to .feed both electrodes simultaneously towards each other connected to said lifting means and to the movable holders of both electrodes to lift the first electrode until said stop is reached and then to operate both electrodes for feeding.

In an arc lamp a pair of are forming electrodes, a support for each electrode, a slidable holder for the electrode on each support and are striking means on one of said slidable holders consisting of a member provided with a collar carrying the electrode and permitting limited longitudinal movement of said electrode, a chain adapted to lift said collar by manual operation and to bring the electrodes together and a weight to hold said collar normally in lowered position and to open arc space between the electrodes.

6. In an arc lamp, a lamp housing, a pair of are forming electrodes and a guiding track within said housing, a carriage slidably supported on said track, said carriage holding a support for each electrode, means on one support for lifting the electrode, a stop to limit the lifting movement, feeding means attached to the holders of both electrodes, means to operate said lifting means and said feeding means held on said carriage and means on the outside of said housing to slide said carriage on its track.

7. In an arc lamp, a lamp housing, a pair of are forming electrodes within said housing angularly disposed to each other, separate guides for each electrode, electrode holders movable on said guides, common feeding means to move both electrode-holders simultaneously on their guides, are striking means on one electrode holder and common means extending without said housing to operate said feeding means and said are striking means consecutively by a single manual movement and its release.

8. In an arc lamp, an electrode support consisting of a guide bar, a plate slidably held thereon, a member having a collar slidably held on said plate to support an electrode, a swinging lever to move said menr her and to form gravity operated means for arc striking on said support, and means on said member to adjust said electrode in relation to said are striking means.

9. In an arc lamp, an electrode support consisting of a guide bar, a plate slidably mounted thereon, a shouldered collar held in said plate, a carbon electrode supported on said collar in axial alinement therewith, a lever on said support, a chain forming means arranged to raise said lever said collar and said electrode and a weight holding said lever normally in inoperative position.

This specification signed this 3d day of April, 1922, at New York, N. Y.

MAURICE J. WVOHL. 

